Aerosol cans for depositing paint and other sprayable materials have been in use for some time. The term “aerosol” as used herein refers to a suspension of liquid or solid particles in a gas. Most aerosol cans are made of tin-plated steel or aluminum. Once an aerosol can has been used and emptied in any of its many possible applications such as for food, beverage, paint and aerosol products, it is in demand for recycling. There are over three billion aerosol cans manufactured in the U.S. annually. Many of the products contained in these cans, such as paint products, light lubricants, starting fluids, polishes and waxes, and cleaners, contain substantial amounts of volatile organic compounds (VOCs) as solvents and include flammable propellants. As a result, partially empty aerosol cans are treated as a hazardous waste at collection centers, military bases, industries utilizing large quantities of aerosols, and treatment, storage, and disposal facilities. Typically, an aerosol package consists of a pressurized liquid product packaged inside a hermetically sealed can that is dispensed through a push button spray tip/valve combination. The pressure is created in the aerosol can via a propellant that atomizes the chemical contents and creates the force to easily dispense the product through the valve/tip in a cost effective manner. The spray delivery which is efficient and effective is commonly used across a wide array of products. The hermetic seal saves the product from contamination during storage.
Some specialized products use a bag or container inside a pressurized can. The liquid product is stored inside the bag and the propellant is inside the space in the can surrounding the bag. The propellant creates pressure on the bag to force the product through the spray tip/valve system for use. This type of aerosol packaging can be expensive and redundant and is typically used in creams and lotions. Given the public's concern about solid waste disposal, the aerosol industry teamed with the steel industry to promote the collection of empty aerosol cans in recycling programs nationwide. Thousands of communities now include aerosol product recycling in both household residential and curbside buy-back and drop-off programs. However, solid waste management firms are questioning the potential safety hazards of processing even ‘empty’ aerosols. This safety question is primarily due to the highly flammable propellants still contained in many cans even when the liquid contents are discharged.
There have been extensive efforts to find alternative solutions to aerosol cans, many of which have proven unsatisfactory. The use of aerosol bags without the can is an option that has not been previously addressed in the prior art. The rigid exterior of a can has been considered essential because of safety concerns for a user in the event that an aerosol bag bursts, causing injury from the propellant materials contained inside the can, or the possibility of fire fueled by these materials. An enormous amount of resources are expended to manufacture cans, collect empty cans, and recycle the empty cans. As a result, it would be highly beneficial to find a solution for deploying aerosol bags but without the can and the propellant. Such a solution would eliminate flammability concerns during dispensing, while still providing the performance results of a spray can application.
In one embodiment of the present invention, a system utilizes a flexible, crushable container similar to the type of container used in some aerosol products, although without a surrounding can and propellant. A dispenser having an elongated housing is provided for receiving the bag. The dispenser is a gun type device that uses a plunger to apply force to the bottom of the bag while the top of the bag with the valve and spray tip is held securely in a slot or valve seat in the other end of the housing. The force exerted by the plunger within the housing creates the hydrostatic pressure inside the bag needed to spray the product through the valve and spray tip. A first trigger and handle on the device are squeezed together to exert force on the plunger. This, in turn, compresses a container spring creating the hydrostatic pressure inside the bag. The user then pulls a second trigger, which activates the valve and dispenses the product. As the product is dispensed, the bag collapses and the container spring extends to its free length. At this point there is little or no pressure on the bag. In a mechanical version of the system, the user renews the cycle by squeezing the first trigger and handle to move the plunger while compressing the container spring and re-creating the hydrostatic pressure needed to dispense remaining product from the bag. The user again pulls the second trigger to dispense the product. This cycle is repeated until the bag is emptied.
In an alternative embodiment of the present invention, a system utilizes a modified flexible, crushable container or bag similar to the type of the first embodiment, or alternatively a rigid or semi-rigid container. The container in this alternative embodiment is provided within a cartridge in the shape of a can and without a propellant. A dispenser for spraying the material may be a standard marking stick or other commercially available dispenser adapted to receive the cartridge with the crushable container. An electrically powered motor assembly is coupled to the cartridge. The motor is used to power a pump that is incorporated into the cartridge to draw the sprayable material from the container. The material is pumped from the container and delivered through a tube to a spray head. The pressure generated by the pump inside the bag and the tube are sufficient to spray the product through the valve and spray tip when valve is opened. A mechanical actuator or switch mounted on the motor assembly and accessible by the user, is activated to turn the pump on and off. When the pump is initially turned on, it creates pressure inside the container and through the tube. The user then pulls a manual trigger mounted on the marking stick or other dispenser, which opens the valve at the spray head dispensing the sprayable material. As the product is dispensed, pressure is maintained by the motor and the container is vacated of material until it is fully emptied.